Hockey and Abbott joined at the hip

Speculation has been rife in recent weeks that Joe Hockey would be dumped as treasurer.

Few would have suspected though it would be a consequence of Tony Abbott losing the prime ministership.

Now Malcolm Turnbull has taken the Liberal leadership from Abbott, Hockey is certain to lose his job as treasurer.

Turnbull said the Abbott government had not been successful in providing the economic leadership the nation needed.

"It is not the fault of individual ministers," he said.

"Ultimately, the prime minister has not been capable of providing the economic leadership ... he has not been capable of providing the economic confidence that business needs."

But a treasurer also has to provide economic leadership.

The economy has slowed, unemployment has risen and a budget surplus seems no nearer than it did under Labor.

There is also a raft of reviews hanging in the air - on tax, federation and competition.

And just as Abbott's popularity has sunk, Hockey's has collapsed.

Abbott and Hockey have been joined at the hip since the coalition came to power in 2013 - through the tough times of Hockey's first budget and a series of political distractions that have dogged two years of government.

Just on Monday, Hockey told 3AW radio the prime minister has always had his support and always will.

"We go back a very long way and I know that Tony Abbott is absolutely dedicated to the best interests of the nation," the treasurer said.

"He is the most selfless and dedicated person I have met in politics".

Depending how the cards fall, Scott Morrison is seen as the minister most likely to replace Hockey.

Morrison was switched from his successful time in the immigration portfolio to give him more experience in budgetary matters as the social services minister.

It would be a tough gig for Morrison to pick-up the pieces - that assumes he doesn't challenge for leadership himself.